Daramola A Olamide
Walter Sisulu University, South Africa
Title: Facile synthesis of L-cysteine CdTe core shell system and its antioxidants properties
Biography
Biography: Daramola A Olamide
Abstract
L-cysteine CdTe core and CdTe/CdSe core-shell were successfully synthesized in an aqueous solution medium. The synthesized QDs were analyzed using UV-vis absorption spectroscopy and florescence spectroscopy, transmission electron microscope (TEM), Fourier transform infra-red spectra (FT-IR) and X-ray powder diffraction (XRD). Systematic investigations were carried out for the determination of optimal condition namely: Reaction times, pH and mole ratios. Compared to CdTe core (529 nm), the core shell (601 nm) demonstrates a drastic shift in wavelength to the red region proving that as extra material had been deposited unto the surface of the core. The 20, 40 and 60 days stability tests conducted proved that core-shell nanoparticles were quite stable compared to the core material. Investigation was also conducted on the total anti-oxidant capacity (TAC) and lipid peroxidation with the use of six (8) Swiss albino mice and this was done using ferric reducing antioxidant power (FRAP) and TBARS was used to malondialdehyde (MDA) concentration. It was discovered that the core-shell demonstrated a poor anti-oxidant property at the heart, spleen, kidney and brain except at the liver where good anti-oxidant property was demonstrated after 24 and 72 hours of exposure. The result at the testis was not significant as against the control. Since this reaction did not involve the use of a nitrogen atmosphere nor special ligand or buffer solutions, it suggests that the process could be easily operated on an industrial scale.
Figure 1: A and B represent the UV and PL spectra for L-Cysteine-CdTe core at pH=11.0, while C demonstrate the Pl emission spectra of L-Cysteine-CdTe/CdSe core shell at 1:1 of Te/Se. The shift in wavelength can be observed between 3 hrs CdTe core and 0 mins CdTe/CdSe core-shell. The TEM image for L-Cysteine-CdTe/CdSe core-shell can be represented by image D while the emission colors of the QDs can be represented by image E.